Rare diseases · Sign or symptom
Areflexia
Absent tendon reflexes
HP:0001284
What it means
Absence of neurologic reflexes such as the knee-jerk reaction.
The stretch reflexes (also called deep tendon reflexes) include the knee-jerk reflex (patellar reflex, the biceps reflex, the triceps reflex, and the ankle jerk reflex or Achilles tendon reflex).
Rare diseases that can present with this102
Very common80–99%
21- Ataxia with vitamin E deficiency
- Cataract-ataxia-deafness syndrome
- Cerebellar ataxia-areflexia-pes cavus-optic atrophy-sensorineural hearing loss syndrome
- Charcot-Marie-Tooth disease type 4G
- Chronic inflammatory demyelinating polyneuropathy
- Cutaneous mastocytosis-deafness-microtia syndrome
- Giant axonal neuropathy
- Hereditary motor and sensory neuropathy, Okinawa type
- Infantile-onset X-linked spinal muscular atrophy
- Microlissencephaly-micromelia syndrome
- Miller Fisher syndrome
- Mitochondrial trifunctional protein deficiency
- Oculocerebrorenal syndrome of Lowe
- Severe X-linked mitochondrial encephalomyopathy
- Spinocerebellar ataxia type 18
- Spinocerebellar ataxia with axonal neuropathy type 2
- Walker-Warburg syndrome
- X-linked Charcot-Marie-Tooth disease type 1
- X-linked Charcot-Marie-Tooth disease type 4
- X-linked Charcot-Marie-Tooth disease type 5
- X-linked intellectual disability, Stevenson type
Common30–79%
44- Abetalipoproteinemia
- Alpers-Huttenlocher syndrome
- Autosomal dominant adult-onset proximal spinal muscular atrophy
- Autosomal dominant optic atrophy and cataract
- Autosomal recessive axonal Charcot-Marie-Tooth disease due to copper metabolism defect
- Autosomal recessive Charcot-Marie-Tooth disease with hoarseness
- Autosomal recessive spastic paraplegia type 66
- Bickerstaff brainstem encephalitis
- CEDNIK syndrome
- Cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome
- Charcot-Marie-Tooth disease type 1B
- Charcot-Marie-Tooth disease type 1F
- Charcot-Marie-Tooth disease type 2B1
- Charcot-Marie-Tooth disease type 4A
- Charcot-Marie-Tooth disease type 4C
- Cockayne syndrome type 3
- COG7-CDG
- Congenital fiber-type disproportion myopathy
- Congenital myasthenic syndrome with glycosylation defect
- Congenital myopathy with myasthenic-like onset
- Gerstmann-Straussler-Scheinker syndrome
- Glycogen storage disease due to acid maltase deficiency
- Glycogen storage disease due to acid maltase deficiency, infantile onset
- Hereditary sensory and autonomic neuropathy due to TECPR2 mutation
- Holmes-Adie syndrome
- Infant botulism
- Lethal ataxia with deafness and optic atrophy
- Lower motor neuron syndrome with late-adult onset
- Neuhauser-Eichner-Opitz syndrome
- Neurogenic arthrogryposis multiplex congenita
- Neutral lipid storage disease with ichthyosis
- Paraparetic variant of Guillain-Barré syndrome
- POEMS syndrome
- Poliomyelitis
- Proximal spinal muscular atrophy
- Recessive mitochondrial ataxia syndrome
- Roussy-Lévy syndrome
- Spinal fast-flow vascular malformation
- Spinocerebellar ataxia type 43
- Spinocerebellar ataxia with axonal neuropathy type 1
- Subacute inflammatory demyelinating polyneuropathy
- TBCK-related encephalopathy-severe hypotonia-craniofacial dysmorphism syndrome
- X-linked Charcot-Marie-Tooth disease type 2
- X-linked Charcot-Marie-Tooth disease type 3
Sometimes5–29%
15- Alternating hemiplegia of childhood
- Autosomal recessive axonal neuropathy with neuromyotonia
- Autosomal recessive centronuclear myopathy
- Autosomal recessive spastic paraplegia type 62
- Autosomal recessive spastic paraplegia type 64
- Birk-Barel syndrome
- Childhood-onset nemaline myopathy
- CNTNAP2-related developmental and epileptic encephalopathy
and 7 more in this range
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions, and Orphanet separately records 1 disease where this sign is specifically absent. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Absent deep tendon reflexes · Absent reflexes · Deep tendon reflexes absent · Loss of deep tendon reflexes · Lost deep tendon reflexes
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.